scholarly journals Corrigendum to “Changes in aquatic vegetation communities based on satellite images before and after pen aquaculture removal in East Lake Taihu”

2021 ◽  
Vol 33 (4) ◽  
pp. 1253-1253
Author(s):  
Journal of Lake Sciences
Keyword(s):  
Satellite Images ◽  
Aquatic Vegetation ◽  
Lake Taihu ◽  
Vegetation Communities ◽  
Before And After ◽  
East Lake

scholarly journals Changes in aquatic vegetation communities based on satellite images before and after pen aquaculture removal in East Lake Taihu

2021 ◽  
Vol 33 (2) ◽  
pp. 507-517
Author(s):  
Yang Jingzhicheng ◽  
◽  
Luo Juhua ◽  
Lu Lirong ◽  
Sun Zhe ◽  
...  
Keyword(s):  
Satellite Images ◽  
Aquatic Vegetation ◽  
Lake Taihu ◽  
Vegetation Communities ◽  
Before And After ◽  
East Lake

scholarly journals Accelerate disaster risk mapping using an automated zonal change detection model for loss estimation and recovery: a flood case study

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Ali Amasha
Keyword(s):  
Change Detection ◽  
Satellite Images ◽  
Flash Flood ◽  
Disaster Risk ◽  
Loss Estimation ◽  
Risk Mapping ◽  
Detection Model ◽  
Applied Model ◽  
High Resolution Satellite Images ◽  
Before And After

Abstract Background The flash flood still constitutes one of the major natural meteorological disasters harmfully threatening local communities, that creates life losses and destroying infrastructures. The severity and magnitude of disasters always reflected from the size of impacts. Most of the conventional research models related to flooding vulnerability are focusing on hydro-meteorological and morphometric measurements. It, however, requires quick estimate of the flood losses and assess the severity using reliable information. An automated zonal change detection model applied, using two high-resolution satellite images dated 2009 and 2011 coupled with LU/LC GIS layer, on western El-Arish City, downstream of Wadi El-Arish basin. The model enabled to estimate the severity of a past flood incident in 2010. Results The model calculated the total changes based on the before and after satellite images based on pixel-by-pixel comparison. The estimated direct-damages nearly 32,951 m2 of the total mapped LU/LC classes; (e.g., 11,407 m2 as 3.17% of the cultivated lands; 6031 m2 as 7.22% of the built-up areas and 4040 m2 as 3.62% of the paved roads network). The estimated cost of losses, in 2010 economic prices for the selected three LU/LC classes, is nearly 25 million USD, for the cultivation fruits and olives trees, ~ 4 million USD for built-up areas and ~ 1 million USD for paved roads network. Conclusion The disasters’ damage and loss estimation process takes many detailed data, longtime, and costed as well. The applied model accelerates the disaster risk mapping that provides an informative support for loss estimation. Therefore, decision-makers and professionals need to apply this model for quick the disaster risks management and recovery.

scholarly journals The distribution of aquatic vegetation in Gonghu Bay, Lake Taihu, 2012

2015 ◽  
Vol 27 (3) ◽  
pp. 421-428 ◽  
Author(s):  
ZHAO Kai ◽  
◽  
LI Zhenguo ◽  
WEI Hongnong ◽  
ZHANG Jing ◽  
...  
Keyword(s):  
Aquatic Vegetation ◽  
Lake Taihu

scholarly journals Initiation of a major calving event on the Bowdoin Glacier captured by UAV photogrammetry

2017 ◽  
Vol 11 (2) ◽  
pp. 911-921 ◽  
Author(s):  
Guillaume Jouvet ◽  
Yvo Weidmann ◽  
Julien Seguinot ◽  
Martin Funk ◽  
Takahiro Abe ◽  
...  
Keyword(s):  
Satellite Images ◽  
Horizontal Shear ◽  
Ice Flow ◽  
Flow Modelling ◽  
Promising Tool ◽  
Before And After ◽  
Aerial Vehicle ◽  
Strain Rate Field ◽  
North Western ◽  
Half Thickness

Abstract. In this paper, we analyse the calving activity of the Bowdoin Glacier, north-western Greenland, in 2015 by combining satellite images, UAV (unmanned aerial vehicle) photogrammetry and ice flow modelling. In particular, a high-resolution displacement field is inferred from UAV orthoimages taken immediately before and after the initiation of a large fracture, which induced a major calving event. A detailed analysis of the strain rate field allows us to accurately map the path taken by the opening crack. Modelling results reveal (i) that the crack was more than half-thickness deep, filled with water and getting irreversibly deeper when it was captured by the UAV and (ii) that the crack initiated in an area of high horizontal shear caused by a local basal bump immediately behind the current calving front. The asymmetry of the bed at the front explains the systematic calving pattern observed in May and July–August 2015. As a corollary, we infer that the calving front of the Bowdoin Glacier is currently stabilized by this bedrock bump and might enter into an unstable mode and retreat rapidly if the glacier keeps thinning in the coming years. Beyond this outcome, our study demonstrates that the combination of UAV photogrammetry and ice flow modelling is a promising tool to horizontally and vertically track the propagation of fractures responsible for large calving events.

scholarly journals Response of Submerged Aquatic Vegetation to Water Depth in a Large Shallow Lake after an Extreme Rainfall Event

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2412 ◽  
Author(s):  
Jinge Zhu ◽  
Jiancai Deng ◽  
Yihui Zhang ◽  
Zhaoliang Peng ◽  
Weiping Hu
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Submerged Aquatic Vegetation ◽  
Community Dynamics ◽  
Aquatic Vegetation ◽  
Lake Taihu ◽  
Extreme Rainfall ◽  
Rainfall Event ◽  
Cumulative Probability ◽  
Extreme Rainfall Event

Submerged aquatic vegetation (SAV) is an important part of lake ecosystems, and a proper SAV community structure is the key factor in keeping a clear-water state. Although the response of SAV to water depth has been widely studied in different aquatic environments, little is known about the response of the SAV community to changes in water depth of a large lake after an extreme rainfall event. To examine this question, 780 samples were collected from Lake Taihu, China, between 2013 and 2017 to analyze the variations in SAV and water depth. The water level of the lake ranged from 2.75 to 4.87 m, and the water depth at sampling sites ranged from 1.07 to 3.31 m. The SAV biomass at the sampling sites ranged from 0 to 17.61 kg/m2. The influence of water depth on SAV biomass and frequency of occurrence differed by seasons and by species. The adaptation of SAV species to increasing water depth is a key element for community dynamics, which in turn contributes to water level regulation. A new method was proposed to identify the optimal water depth for SAV biomass accumulation based on calculation of the cumulative probability and probability density.

Effect of landslides on the structural characteristics of land-cover based on complex networks

2017 ◽  
Vol 31 (22) ◽  
pp. 1750156 ◽  
Author(s):  
Jing He ◽  
Chuan Tang ◽  
Gang Liu ◽  
Weile Li
Keyword(s):  
Land Cover ◽  
Complex Networks ◽  
Power Law ◽  
Satellite Images ◽  
Structural Characteristics ◽  
Power Law Distribution ◽  
Graph Topology ◽  
Linear Coefficient ◽  
Area Distribution ◽  
Before And After

Landslides have been widely studied by geologists. However, previous studies mainly focused on the formation of landslides and never considered the effect of landslides on the structural characteristics of land-cover. Here we define the modeling of the graph topology for the land-cover, using the satellite images of the earth’s surface before and after the earthquake. We find that the land-cover network satisfies the power-law distribution, whether the land-cover contains landslides or not. However, landslides may change some parameters or measures of the structural characteristics of land-cover. The results show that the linear coefficient, modularity and area distribution are all changed after the occurence of landslides, which means the structural characteristics of the land-cover are changed.

scholarly journals Changes of water temperature and heat flux at water-sediment interface, East Lake Taihu

2018 ◽  
Vol 30 (6) ◽  
pp. 1599-1609 ◽  
Author(s):  
ZENG Ye ◽  
◽  
ZHU Jinge ◽  
WANG Yanping ◽  
HU Weiping
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Lake Taihu ◽  
East Lake ◽  
Sediment Interface

scholarly journals APPLICATION OF OFF-NADIR SATELLITE IMAGERY IN EARTHQUAKE DAMAGE ASSESSMENT USING OBJECT-BASED HOG FEATURE DESCRIPTOR

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 167-171
Author(s):  
S. Jabari ◽  
M. Krafczek
Keyword(s):  
Change Detection ◽  
Damage Detection ◽  
Disaster Management ◽  
Satellite Images ◽  
Feature Descriptor ◽  
Object Based ◽  
Before And After ◽  
Map Generation ◽  
Spectral Comparison ◽  
Damage Map

<p><strong>Abstract.</strong> One of the most crutial applications of very-high-resolution (VHR) satellite images is disaster management. In disaster management, time is of great importance. Therefore, it is vital to acquire satellite images as quickly as possible and benefit from automatic change detection to speed up the process. Automatic damage map generation is performed by overlaying the co-registered before and after images of the area of interest and, compring them to highlight the affected infrastructures. For speeding up image capture, satellites tilt their imaging sensor and take images from oblique angles. However, this kind of image acquisition causes severe geometric distortion in the images, which hinders image co-registration in automatic change detection. In this study, a Patch-Wise Co-Registration (PWCR) solution is used. In this algorithm, the before and after images are co-registered in a segment-by-segment manner. From the literature, this algorithm is followed by a spectral comparison to detect changes. However, due to the complicated structure of debris in damage detection applications, spectral comparison methods cannot perform well. In this work, we developed an object-based method using Histogram of Oriented Gradient descriptor to detect damges and compared our results to different existing spectral and textural change detection methods. The algorithm is tested on images from the 2010-Heidi earthquake, captured by DigitalGlobe. The achieved highly accurate results demonstrate the potential of using off-nadir remote sensing images for automatic urban damage detection possibly in early response systems as it speeds up the damage map generation by providing flexibility to utilize images taken from different anlges.</p>

scholarly journals The Study on Natural Restoration of Aquatic Vegetation in the Northern Lakeside, Lake Taihu

2002 ◽  
Vol 14 (1) ◽  
pp. 60-66 ◽  
Author(s):  
YANG Longyuan ◽  
◽  
LIANG Haitang ◽  
HU Weiping ◽  
JI Jiang ◽  
...  
Keyword(s):  
Aquatic Vegetation ◽  
Lake Taihu ◽  
Natural Restoration
Sign in / Sign up

Export Citation Format

Share Document